The present invention relates to a plastic pin, including socalled bowling pins, for bowling lanes, and also relates to a method of making such a pin. The pin has a hard shell and surrounds a core of cellular and/or porous polymeric material. The shell, and the hollow interior that it surrounds, are provided in the lower portion of the pin with a bulging portion, thereabove a reduced diameter portion, and thereabove an again widening head. Furthermore, in the region of the reduced diameter portion there is provided in the hollow interior a transverse wall that divides the hollow interior and has a venting hole.
The transverse wall makes it possible to fill only the lower portion of the hollow interior with the cellular and/or porous polymeric material, so that the upper portion of the hollow interior remains empty and contains merely air. This division of the hollow interior is advantageous for influencing the center of gravity and the tipping characteristic of the pin.
With the heretoforeknown pins of this type, the transverse wall extends monolithically from one wall of the shell to the opposite wall. The manufacture of such pins is therefore complicated, since the pin shell must practically contain two hollow chambers. See, for example, U.S. Pat. No. 5,569,093.
The present invention proceeds from the recognition that it would be advantageous if during formation of the pin shell such a shell could be made as a single piece, and that it is readily possible to provide in the base of the shell openings that can later be closed off and that are already required for introduction of the material that serves for filling the hollow interior.
It is therefore an object of the present invention to simplify the manufacture of the pin in such a way that a component that forms a transverse wall is introduced only after the shell has been formed or shaped.